UKCEH Land Cover Plus: Hedgerows 2016-2021 (England)

This model was produced by collating Environment Agency airborne lidar data, Land Cover Map (LCM) linear data, and Ordnance Survey (OS) data. The lidar data were filtered and pixels were removed based on their attributes and coincidence with OS data (masking). Vectorized output was used to classify a linear framework of the LCM, creating a classified polyline model of linear features.

The model was validated by ‘ground-truthing’ against 38 test squares of 1 km^2 each, which were surveyed on the ground by trained fieldworkers in 2022 using Countryside Survey methods. The results showed good agreement between the lidar model and the ground-truthing, allowing for a spatial buffer tolerance around features to account for the different linear frameworks they were based upon. At the summary scale across all test squares, the total woody feature lengths showed a 96% agreement. At the scale of individual test squares, there was an average 76% agreement of woody feature lengths within a 20 m buffer tolerance. Height classifications of the model showed an exact agreement for 32% of the total feature length, and 63% agreement within a tolerance of one class above or below.